<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>伪元素选择器 </title>
    <style>
      div{
        width: 300px;
        height: 300px;
        background-color: pink;
      }
      div::before{
        content: "老鼠";
        color: blue;
      }
      div::after{
        content: "大米";
        width: 100px;
        height: 100px;
        background-color: red;
      }
    </style>
</head>
<body>
    <!-- 老鼠爱大米 -->
    <div>爱</div>
</body>
</html>